Centrifugal switch.



W. J. BRANSOIL CENTBIFUGAL SWITCH.

nlLloA'rmll FILED snr'x'. a, noa.

Patented Dec. 6,1910.,

2 BHBETFBHEET 1.

ATTonNEY W.J. BRANSON. CENTBIPUGAL SWITCH.

ArrLxonIon rmm sur. s, 190s.

Patented Dc. 1910.

UNITED STATES PgrENT oFFioE.

' WALTER. J. EnANsoN, or wILKINsiaiJItG,l FiNNsILVANIA,l AssIeNoE., BY MEsNE ASSIGNMENTS, To wEsTINGHoUsE vELECTRIC a MANUFACTURING COMPANY, 0E .IITT'sBUE PENNsxLvANIA, A CORPORATION 0E PENNSYLVANIA.

CENTBIEUGAI. swITciIf Patented Dee. e, 1910.

App'umm sied september s, isos. serial No. 452,991.

To all whom it may concern:

Be it known that I, WALTER J. BnANsoN, a citizen of the United States, and a resident ofiWilkinsbur in the county of Alleglieny and State o Pennsylvania, have invented a new and useful Im rovement in Centrifugal Switches, of whic the following is a specification.

My invention relates tol centrifugal switches suoli as are commonly employed in connection with single-phase induction mo# tors, and it has for its object to provide a lswitch of exceptionally simple and economical construction, and by means of which sparking within a motor may be substant1 ally obviated.

and a rotata le secon ary member 5for the shaft l6 of which bearings 7 are provided in the ends of the casing2. Duringk operation-2 the main primary windin 3 is maintairie l in connection with a siiita le supply circuit,

(not shown A, while the auxiliary winding 4t 'is connecte to the circuit by means of the centrifugal switch whichconstitutesv the present invention only during, and for the purpose lof assisting, the,V starting of the motor. 1 Y. ,A

The centrifugal switch, just referred to, comprises two continuous rin s 8 and 9 which loosely surround the sha t 6., and are of different widths, the inner ruig protruding at one end -rom the'outer. ac of the rings 8 and 9 .is provided with a pair 4of radially projecting lugs'lO which are riveted -or ,otherwise suitably secured to an annular insulatin rin 11 which, in turn, is secured to the en f t e casing 2. 4The lugs 10 constitute'conf-'enient means for connecting the terminwis of the a. 'liary winding 4 to the Y rings. The swit' comprises, further, an

single-phase induction motors, with main l annular bracket 12 that is riveted or otherwise suitably secured to an annular'insulating ring 13, the latter Abeing secured to the end of lthe rotatable member 5. The bracket 12 is provided with diametrically opposite extensions 14 to which brushes '15 are ivotally secured, and with other diametrica y opposite extensions 16, between which and the brushes helical tension springs 17 are interposed for the purpose of normally maintaining the brushes respectively in engagement with the stationary rings.

When the brushes 15 engage the stationary rings 8 and 9, vthe circuit of the auxiliary winding is complete because the annular bracket 12 electrically connects the brushes together. When, however, the motor attains such predeterminedspeed that the auxiliary primary winding need no longer be employed, the centrifugal force exerted on account ot' the rotation of 4the secondary member 5 causes the brushcsl to move substantially radially outward and out of engagement with the stationary rings 8 and 9, thus interrupting the circuit of the auxiliary winding. It will be seen that the circuit is interrupted as soon as one'of the brushes is moved out of engagement with the corresponding` ring, a-rcingbetween the remaining brush and its corresponding ring does not occur, even if the said parts remain in engagement. Be 'cause of this action, it is not necessary that the springs 17 be so adjusted as to permit the brushes to move synchronously out of engagement with the rinfgs, as is necessary7 in many switches hereto ore employed.

I claim as my invention: y

1. A centrifugal switch comprising st'a-` tionary concentric terminal cylinders of different-lengths, and electrically connected rotatable brushes that are maintained in engagement with the respective cylindersex- 4cept when rotated at greater than a predewith the result. thatv and electrically connectedand electrically connected rotatable brushes that are maintained in engagement with the respective cylinders except when' rotated at greater than a predetermlned speed.

4. In an induction motor, the combination with relatively rotatable rimary and secondary members, main and auxiliary windings for the primary member,. stationary concentric rings of different lengths sur-A roundingthe shaft of .the rotatable member and interposed in the clrcuit of the auxilia Winding, and electrically connected brushes carried by the rotatable member and maintained respectively in engagement with the rings except when the motorattains a predetermined speed.

'In testimony whereof, I have hereunto -subscribed my name this 3rd lday of Sep-- a Witnesses:l

F. R. KUNKE BIRNEY Hunts.v 

